In recent years, rapid progress has been made in the development of techniques to reduce the size and weight of mobile phones, which are a representative example of electronic apparatuses, and to make them multifunctional. As technical trends, in place of flexible printed circuit boards (hereafter, referred to as “FPCs”), there are increasing demands for micro coaxial cable assemblies as internal wiring materials for mobile phones. This is because the transmission characteristics and noise resistance characteristics of micro coaxial cables meet market demands.
Further, there have been demands for a wiring method that makes it possible to use micro coaxial cables even in mechanical constructions which have been regarded to be unsuitable for the use of the micro coaxial cables.
Conventional micro coaxial cable assemblies have been adopted in place of FPCs as internal wiring materials for mobile phones. The mechanical structures of mobile phones which adopt the micro coaxial cable assemblies include an open-close structure, called a “clamshell” type structure, shown in FIG. 7A, a rotating structure, called a “jackknife” type structure, shown in FIG. 7B, and a dual-axis structure enabling both rotation and opening/closing, called a “twist” type structure, shown in FIG. 7C. However, the micro coaxial cable assemblies have not been used for a parallel-displacement structure, called a “slide” type structure, shown in FIG. 7D.
Characteristics required for the slide-type structure include horizontal sliding in a space of a height of 3 mm. In the related art, only FPCs having a thin-film form have been applicable to such a structure. FIG. 8 illustrates an example of the application of an FPC 4 as a wiring material between casings of a slide-type electronic apparatus 1. In the electronic apparatus 1, circuits of a first casing 2 and a second casing 3 that is slidably mounted to the first casing 2 are electrically connected to each other by the FPC 4.
As an example of multi-core cables used in micro coaxial cable assemblies or the like, there have been proposed techniques disclosed in Patent Documents 1 and 2.
Patent Document 1 discloses a multi-core cable in which both ends of each of a plurality of wires are arranged in a flat shape with predetermined pitches and the central portion is bundled into a single cable.
Patent Document 2 discloses a multi-core cable in which a weft is woven among a plurality of wires, and the wires are bundled into a shape approximating a round shape by contraction of the weft.
[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2005-235690
[Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2005-141923